1. Field of the Invention
The present invention relates to a printer that intermittently feeds printing sheets to which a photoconductive microcapsule is applied in a sheet feeding direction and prints images thereon and a printing system using this printer.
In this specification, a "photoconductive microcapsule" indicates a micro-capsule that is constituted to be readily collapsible or hardly collapsible, in other words, a latent image is formed when it is irradiated with the light of a specific wave length area and in which a coloring material capable of forming or developing a specific color when it is collapsed is contained, more typically sealed.
2. Description of the Related Art
A printer of a type that printing sheets to which a photoconductive micro-capsule is applied are intermittently fed in a sheet feeding direction and images are printed thereon is disclosed in Japanese Unexamined Patent Publication No. 10-48801 and Japanese Unexamined Patent Publication No. 10-147027. The printer of this type comprises a carriage capable of reciprocating in a scanning direction substantially perpendicular to the sheet feeding direction of the printer, an exposure head or a printing head fixed to the carriage and a pressing and developing head attached to the carriage on the downstream side of the exposure head with respect to the sheet feeding direction. Further, in this printer, as the carriage moves in the scanning direction, the exposure head performs exposing and scanning operations relative to an area of one line on the sheet to be exposed and scanned and the pressing and developing head simultaneously performs pressing, developing and scanning operations relative to an area of one line on the sheet to be developed and scanned on which a latent image is formed after an exposing process.
In such a conventional printer, since the exposure head and the pressing and developing head are integrally supported by the carriage, the pressing force of the pressing and developing head is supported by the carriage and the carriage is supported by a supporting body thereof, when the carriage supporting the pressing and developing head receives such a force as to separate the carriage from the sheet upon pushing operation by the pressing and developing head, the supporting body for supporting the carriage may be possibly slightly bent, so that there is a fear that the distance between the exposure head supported by the carriage and the sheet is varied. Further, since the supporting body of the carriage serves as a guide for moving the carriage in the scanning direction, there is a fear that clearance between the carriage and its supporting body due to abrasion or the like. Therefore, when the carriage supporting the pressing and developing head receives such a force as to separate the carriage from the sheet upon pushing operation by the pressing and developing head, the position of the carriage relative to the supporting body shifts from a prescribed position due to the reaction against the pressing force of the pressing and developing head, hence there is a fear that the positional relation between the exposure head and the sheet shifts from a prescribed state. As a consequence, in such a printer, conditions for exposing the sheet by the exposure head, that is to say, conditions for forming a latent image vary, so that it may be possibly difficult to form and print a prescribed latent image (formation of the latent image and pressurizing development).
Note that, as a pressing and developing device, has been known a printer of a type which uses a pair of rollers having the length corresponding to the width of a sheet and rotating about the axis in a width direction of the sheet and in a sheet feeding direction (disclosed in Japanese Unexamined Patent Publication No.10-48800). However, since the printer of this type is not designed to scan a pressing and developing head, all the areas of the width of the sheet need to be pressed uniformly and simultaneously. Therefore, not only an extremely great pressing force is required, but also widthwise entire areas may be possibly scarcely developed uniformly.